A parabolic or other suitably shaped reflector is a well known device for the transmission or reception of electromagnetic energy. When employed as a transmitting antenna, a feed horn located at the focus of the reflector directs microwave energy toward the reflecting surface of the reflector. The surface of the reflector then serves to reflect the waves from the feed horn into space in the form of plane waves. Conversely, when employed as a receiving antenna, a microwave reflector reflects plane waves from space toward a feed horn located at the focus of the reflector. Whether operating in the mode of a transmitter or receiver, the feed horn is typically connected by means of a waveguide to a transmission line originating behind the surface of the reflector. The waveguide is appropriately curved so as to minimize interference with microwave energy passed between the feed horn and the reflector. Typically, the step of bending the waveguide in the prior art requires the use of an internal mandrill to avoid deforming the interior cross section of the waveguide. Nevertheless, bending of the waveguide creates imperfections in the interior cross section of the waveguide which contribute to energy losses in the reflector system. Energy losses may also be caused by imperfections in the waveguide, feed horn or reflector. Prior art feed horn assemblies further contribute to energy losses in that their waveguide and feed horn frequently consist of multiple components which are joined together by a brazing process resulting in an imperfect interface between the components. As a result of the above imperfections and associated energy losses, feed systems known in the art must commonly undergo an extensive tuning process before they may be operated efficiently.
The present invention is directed to overcoming or at least reducing the effects of one or more of the problems set forth above.